The Open Dictionary

inconceivable

adjective

UK/ˌɪn.kənˈsiː.və.bᵊl/
US/ˌɪn.kənˈsiː.və.bᵊl/

Definitions of inconceivable adjective

  1. C2

    Not capable of being imagined or comprehended; beyond belief.

    • The prospect of not succeeding was utterly inconceivable to them.

    • It’s inconceivable that she would ever alter her decision.

    • For someone with such a track record of success, failure is inconceivable.

  2. Highly improbable or unlikely; difficult to believe.

    • It is almost inconceivable that a nuclear incident would occur again in the same location.

    • It is not inconceivable that she might be fabricating the story.

    • Given all factors, it is inconceivable they did not succeed.